I see this thread lingers on without further comment from its originator, as many on Brickboard do. But these threads get dug up all the time in searches, so I think some facts need to be added to the speculation.

1) A 1991 240, whether LH2.4 or LH3.1 does indeed come equipped with a cold start injector in North America. The 5th injector, installed in the intake manifold's nether regions is done away with in 1992-93 production. Beginning in '92, an ECU change gives the 4 service injectors the job of cranking enrichment, and the fuel rail is made without the cold start tap, and includes a Schrader valve for pressure testing.

2) It is unlikely a car that came with one would be "missing" one without having been properly modified (with parts from the 92-93 version) or worse. Just having one "missing" would result in a car with a huge fuel leak.

My guess is the same as the OP's -- that is the terminology is mistaken -- that perhaps the air intake pre-heater thermostat and pipe are the items the PO referred to as "missing" which is what we commonly do to protect the AMM from overheating. These might affect warm-up emissions and even possibly some drivability right from start in a climate like Northern Sweden, but not Georgia.

--
Art Benstein near Baltimore

Sometimes I wonder if our lives are all about the challenge of keeping gases and liquids where they belong.